Arc-lamp.



'G. E. STEVENS.

ARC LAMP.

APPLICATION FILED AUG.14, 1003.

928, 1 61. Patented J l 13, 1909.

IIIIIIIIIIIIIIIIIMIL I Witnesses: Inventor;

j 9 George E. Stevens.

UNITED STATES PATENT OFFTQE GEORGE E. STEVENS, OF LYNN, MASSACHUSETTS, ASSIGN OR TO GENERAL ELECTRIC COM-'- PANY, A CORPORATION OF NEW YORK.

ARC-LAMP.

To all whom it may concern:

Be it known that I, GEORGE E. STEVENS, a citizen of the United States, residing at Lynn, in the county of Essex, State of Massachusetts, have invented certain new and useful Im rovements in Arc Lamps, of which the following is a specification.

The object of my present invention is to improve and simplify the construction of arc lamps. I accomplish this result by the employment of certain novel features of construction and arrangement of the regulating coils or windings of the lamps and certain other improvements in the construction of the feeding mechanism of the lamp.

For a better understanding of my invention reference may be had to the accompanying drawings in which I have illustrated an arc lamp embodyin my invention.

Of the drawings, Tigure 1 is a perspective view illustrating the assembled arc lamp; Fig. 2 is a sectional elevation showing the construction of the feed magnet and its armature; Fig. 3 is a plan view showing a device for securin and making a connection with the termina s of coils; Fig. 4 is a sectional elevation showing the construction and arrangement of the resistance conductor and su porting parts; Fig. 5 is a view taken similafly to Fig. 2 showing a modified construc tion of winding; and Fig. 6 is a section taken above the follower in Fig. 1 showing the connection between the electrode follower and its guides.

Referring to the drawings, 1 represents a hood of ordinary construction from which depend a pair of parallel posts 2. These posts support at their lower ends a pair of parallel platforms 3 and 4 which may be formed integrally with each other or not as desired and are separated by space blocks 5 and 6. A third platform 7 is secured beneath the platform 4. Preferably the platform 7 is provided with a pair of integrally formed upwardly extending legs or projections 8 8. Bolts 9 pass through the platform 4 into axial threaded holes formed in the ends of the projections 8 and 8 to secure the platforms 4 and 7 together. The lower electrode 10 of the lamp is carried by an arm 11 which depends from the platform 7.

The platform 3 carries upon its upper side a pair of solenoid coils 12 12. The solenoid coils 12 12 are similar to each other and are Specification of Letters Patent.

Application filed August 14, 1903.

Patented July 13, 1909.

Serial N0. 169,474.

characterized by the fact that they are formed out of a ribbon conductor shaped into a helix with the plane of the ribbon substantially perpendicular to the axis of the helix. The coil thus formed is in the form of a tubular shell the thickness of the shell being the width of the ribbon. Successive turns of the helix are separated by a thin layer of suitable insulating material. Preferably the material employed as insulation is practically incombustible and may consist of fire clay mixed with a solution of silicate of soda or some similar composition which may be inserted between the turns of the helix referably in the form of a paste. Ordinari y no effort is made to cover the edges of the ribbon with insulation as it is unnecessary. The coils are however insulated from the platform 3.

The coils support at their upper ends a cross-head or connecting piece or member 13. This member is insulated from the coils 12 12. A post 14 which may be threaded into the platform 3 as is clearly shown in Fig. 2 passes upward between the coils 12 and 12 through an aperture formed for the purpose in the connecting piece 13. The stationary member 15 of a dash-pot is formed with a threaded axial opening in its bottom into which the upper end of the rod 14 is threaded. The member 15 thus forms a nut by means of which the coils 12 and 12 may be rigidly clamped between the platform 3 and the connecting member 13. By reason of the construction of the coils 12 and 12 out of an edgewise wound conductor, the necessity for a supporting frame or spool or the like upon which the coils 12 and 12 are formed is done away with as the tubular coil formed is self-supporting thus greatly simplifying the construction of the lamp.

The movable member 16 of the dash-pot has connected to it one end of each of a pair of bent rods 17 of non-magnetic material. The other ends of the rods 17 are secured to the ends of the legs of a U-shaped armature 18. Preferably the armature 18 is provided with an insulating covering which prevents any damage resulting from an accidental contact between the armature and the coils. This covering may be made of vitreous enamel, or the like. The legs of the magnet 18 pass through apertures formed for the purpose in the platform 3 into the tubular bores of the coils 12 1.2. The portion of the armature 18 connecting the legs plays be tween the platforms 3 and 4. A suitable link 19 carried by this portion of the core or armature is connected to the clutch-operating lever 20 which serves to feed the upper electrode 21 in the usual manner.

The lower terminals of the conductors forming the coils 12 12 are connected together at the bottom by a connecting member 22. The connecting member 22 comprises two portions 23 23 each formed with teeth or spokes 24. The portions 23 23 are connected by a portion 25. The lower turn of the coil 12 is connected to the portion 23 of the member 22 by threading it under and over the teeth or spokes 24 as shown at the left hand of Fig. 3. A similar connection not shown is made between the coil 12 and the annular portion 23. when the coils 12 and 12 are clamped into position this arrange ment of the end of the conductor and. the teeth 24 insures a very good electrical contact and at the same time firmly locks the ends of the conductors in place.

The resistance coils 26 and 2 which surround the projections 8 8 respectively, being separated therefrom by suitable insulating material, are constructed similarly to the coils 12 and 12 out of edgewise wound rib bons and are connected. at their upper ends by a conductor 27 which is similar to the connecting conductor 22. The coils which are compressed between the platforms 4 and 7 by the bolts 9, tapped into the projections 8 and 8 add materially to the mechanical rigidity and strength of the lamp structure. Preferably, the materials out of which the coils 26 and 26 and 12 and 12 respectively are formed are different, the conductivity of the material out of which the coils 12 and 12 is formed being much higher than that out of which the coils 26 26 are formed. The coil 26 is insulated from the platforms 4 and 7 and the coil 26 is insulated from the platform 4. The lower terminal of the coil 26 however is in electrical contact with the platform 7 at the point 26.

In order to vary the portion of the coils 26 26 which is in circuit and thereby vary the resistance of the circuit including the coils, the coil 26 is surrounded by a split conducting ring 28. The conducting ring 28 may be adjusted along the length of the coil 26 and may be clamped. about the coil at any desired point. When so clamped good electrical contact is made between the ring and the outer bare edges of the ribbon forming the portion of the coil embraced. The ring 28 may be adjustably connected to a lead 29 which is in turn connected to one of the terminals of the lamp. The other terminal of the lamp is connected to the upper endof the conductor forming the coil 12 through a lead 30. The upper end of the conductor forming the coil 12 is connected to the upper end of the movable electrode 21 through a suitably insulated flexible conductor 31.

The upper end of the electrode 21 is held in a clamp carried by a follower 21. The follower 21 is preferably made out of incombustible insulating material such as porcelain or similar vitreous material, and is shaped so as to be guided by the posts 2. It is proportioned to have a weight which will insure a proper feed of the electrode. The use of porcelain for this purpose is highly advantageous as it is noncombustible, non-conducting, is easily made in the form desired and possesses considerable mechanical strength.

The circuit of the lamp is as follows: from the lead 30 through the coils 12 and 12, conductor 31., upper electrode 21, lower electrode 10, arm 11 to the lower platform 7 ,the coil 26, connecting conductor 27 and that portion of the coil 26 above the split ring 28, to the lead 29.

In the construction shown in Fig. 5 I have illustrated a modification of my invention in which the conductor employed to form the regulating coils is shown as curved so that a section of the conductor taken transversely to its length is are shaped. l'vith this constructionadjacent turns nest in one another and, when the turns are pressed together, the mechanical strength of the coil and the re sistance to the sidewise displacement of the turns is much increased. This modification which 1 have shown as embodied in the magnet coils can of course be employed in forming the coils 26 and 26 and indeed is useful in other relations than those shown.

The operation of the feed mechanism of the lamp will be readily understood by all those skilled in the art and need not be described in detail here.

By the use of the edge-wound ribbon coils insulated with fireproof material, an exceedingly simple and durable construction of lamp is obtained. The arrangement of the coils of the lamp is such as to insure the =highest possible amount of mechanical strength with the materials employed. The lamp is practically indestructible from any excess of current to which it may be subjected. Moreover the fireproof qualities of the coils allow them to be placed where desired without regard to the temperature to which they may be subjected at that point.

While I am aware of the fact that edgewise wound coils have been employed in the con struction of dynamo-electric machines and for certain other similar purposes, I believe that I am the first to discover the peculiar advantages possessed by this form of winding when used in arc lamps and which were not suggested by the use of such windings in dynamo-electric machines or similar places and am the first to apply this form of winding to are lamps.

What I claim as new and desire to secure I by Letters Patent of the United States, is,

1. In an arc lamp, a frame work comprising a lamp top, a platform, and a pair of parallel rods uniting them, a movable electrode, and a follower formed out of insulating noncombustible material to which said electrode is connected, said follower being arranged to slide on said rods.

2-. In an arc lamp, a frame-work comprising a lamp top, a platform, and a pair of parallel rods uniting them, a movable follower block formed out of vitreous material, arranged to slide on said rods.

3. In an arc lamp, a frame-work comprising a lamp top, a platform, and a pair of parallel rods uniting them, a movable electrode, and a follower-block formed out of porcelain to which said electrode is connected, said follower being arranged to slide on said rods.

4. In an arc lamp, the combination of a set of regulating coils, a supporting base for one end of the same, a head plate at the other end of the coils, a rod extending between the base and head plate, and a dashpot the stationary member of which cooperates with the rod to clamp the coils between the suppoi-tin base and head plate.

5. In an arc lamp, a frame-work comprising a lamp top, a platform, and a pair of parallel rods uniting them, a movable electrode, and a follower-block therefor formed out of inslulating material arranged to slide on said roc s.

6. In an arc lam a frame-work comprising a lamp top, a p atform and a pair of parallel posts uniting them, a movable electrode, a holder therefor, and a follower-block of insulating material to which said holder is connected, said follower-block being guided by said osts.

7. 11 an arc lam a, a frame-work comprising a lamp top, a platform and a pair of parallel posts uniting them, a movable electrode, and a follower-block made out of insulating non combustible material, said followerblock being guided by said posts.

8. In an arc lamp, a platform or support, a l

feed magnet carried thereby, and means for clamping the windings of said magnet in place comprising a bolt extending from said platform and a nut cooperating therewith and formed out of one member of a regulating dash-pot of the lamp.

9. In an arc lamp, two coils, a U-shaped armature entering said coils at one end, a clamping member bearing upon the other end of the coils, a dashpot having one member secured directly above the magnet, and rods connecting the ends of the U-shaped armature to the other member of the dashpot.

10. In an arc lamp, two coils, a U-shaped armature entering said coils at one end, a clamping member bearing upon the other end of the coils, a dashpot having one member secured directly above the magnet, and rods of non-magnetic material connecting the ends of the U-shaped armature to the other member of the dashpot.

11. In an arc lamp, a platform or su port, a feed-magnet coil carried thereby, a 0 amping plate engaging one end of said coil, a bolt connected to said platform and extending through said clamping plate, a nut on said bolt, a movable member forming with said nut a dash-pot, an armature operatively related to said coil, and a connection between said armature and the movable dash-pot member.

12. In an arc lamp, a platform or support, a feed-magnet consisting of a plurality of coils resting upon said platform, a clamping plate engaging the ends of said coils, a screwthreaded member for forcing said plate against said platform, a movable member forming with said screw-threaded member a dash-pot, a Ushaped armature associated with said coils, and means connecting the ends of said armature to the movable dashpot member.

In witness whereof, I have hereunto set my hand this twelfth day of August, 1903.

GEORGE E. STEVENS.

Nitnesses DUGALD MoK. MoKILLoP, JOHN A. McMANUs. 

